1//===-- MachException.cpp ---------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Created by Greg Clayton on 6/18/07.
10//
11//===----------------------------------------------------------------------===//
12
13#include "MachException.h"
14#include "DNB.h"
15#include "DNBError.h"
16#include "DNBLog.h"
17#include "MachProcess.h"
18#include "SysSignal.h"
19#include <cerrno>
20#include <inttypes.h>
21#include <sys/ptrace.h>
22#include <sys/types.h>
23
24static void AppendExceptionData(std::vector<mach_exception_data_type_t> &out,
25 mach_exception_data_t data,
26 mach_msg_type_number_t count) {
27 mach_exception_data_type_t buf;
28 for (mach_msg_type_number_t i = 0; i < count; ++i) {
29 // The input Data we receive need not be aligned correctly.
30 // Perform an unaligned copy by pretending we're dealing with
31 // a char* buffer. This is required to work around UBSAN/ASAN
32 // "misaligned address" errors.
33 auto *src = reinterpret_cast<char *>(data + i);
34 memcpy(&buf, src, sizeof(mach_exception_data_type_t));
35 out.push_back(buf);
36 }
37}
38
39// Routine mach_exception_raise
40extern "C" kern_return_t
41catch_mach_exception_raise(mach_port_t exception_port, mach_port_t thread,
42 mach_port_t task, exception_type_t exception,
43 mach_exception_data_t code,
44 mach_msg_type_number_t codeCnt);
45
46extern "C" kern_return_t catch_mach_exception_raise_state(
47 mach_port_t exception_port, exception_type_t exception,
48 const mach_exception_data_t code, mach_msg_type_number_t codeCnt,
49 int *flavor, const thread_state_t old_state,
50 mach_msg_type_number_t old_stateCnt, thread_state_t new_state,
51 mach_msg_type_number_t *new_stateCnt);
52
53// Routine mach_exception_raise_state_identity
54extern "C" kern_return_t catch_mach_exception_raise_state_identity(
55 mach_port_t exception_port, mach_port_t thread, mach_port_t task,
56 exception_type_t exception, mach_exception_data_t code,
57 mach_msg_type_number_t codeCnt, int *flavor, thread_state_t old_state,
58 mach_msg_type_number_t old_stateCnt, thread_state_t new_state,
59 mach_msg_type_number_t *new_stateCnt);
60
61extern "C" boolean_t mach_exc_server(mach_msg_header_t *InHeadP,
62 mach_msg_header_t *OutHeadP);
63
64// Note: g_message points to the storage allocated to catch the data from
65// catching the current exception raise. It's populated when we catch a raised
66// exception which can't immediately be replied to.
67//
68// If it becomes possible to catch exceptions from multiple threads
69// simultaneously, accesses to g_message would need to be mutually exclusive.
70static MachException::Data *g_message = NULL;
71
72extern "C" kern_return_t catch_mach_exception_raise_state(
73 mach_port_t exc_port, exception_type_t exc_type,
74 const mach_exception_data_t exc_data, mach_msg_type_number_t exc_data_count,
75 int *flavor, const thread_state_t old_state,
76 mach_msg_type_number_t old_stateCnt, thread_state_t new_state,
77 mach_msg_type_number_t *new_stateCnt) {
78 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) {
79 DNBLogThreaded("::%s ( exc_port = 0x%4.4x, exc_type = %d ( %s ), exc_data "
80 "= 0x%llx, exc_data_count = %d)",
81 __FUNCTION__, exc_port, exc_type,
82 MachException::Name(exc_type), (uint64_t)exc_data,
83 exc_data_count);
84 }
85 return KERN_FAILURE;
86}
87
88extern "C" kern_return_t catch_mach_exception_raise_state_identity(
89 mach_port_t exc_port, mach_port_t thread_port, mach_port_t task_port,
90 exception_type_t exc_type, mach_exception_data_t exc_data,
91 mach_msg_type_number_t exc_data_count, int *flavor,
92 thread_state_t old_state, mach_msg_type_number_t old_stateCnt,
93 thread_state_t new_state, mach_msg_type_number_t *new_stateCnt) {
94 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) {
95 DNBLogThreaded("::%s ( exc_port = 0x%4.4x, thd_port = 0x%4.4x, tsk_port = "
96 "0x%4.4x, exc_type = %d ( %s ), exc_data[%d] = { 0x%llx, "
97 "0x%llx })",
98 __FUNCTION__, exc_port, thread_port, task_port, exc_type,
99 MachException::Name(exc_type), exc_data_count,
100 (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD),
101 (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD));
102 }
103
104 return KERN_FAILURE;
105}
106
107extern "C" kern_return_t
108catch_mach_exception_raise(mach_port_t exc_port, mach_port_t thread_port,
109 mach_port_t task_port, exception_type_t exc_type,
110 mach_exception_data_t exc_data,
111 mach_msg_type_number_t exc_data_count) {
112 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) {
113 std::vector<mach_exception_data_type_t> exc_datas;
114 AppendExceptionData(exc_datas, exc_data, exc_data_count);
115 DNBLogThreaded("::%s ( exc_port = 0x%4.4x, thd_port = 0x%4.4x, tsk_port = "
116 "0x%4.4x, exc_type = %d ( %s ), exc_data[%d] = { 0x%" PRIx64
117 ", "
118 "0x%" PRIx64 " })",
119 __FUNCTION__, exc_port, thread_port, task_port, exc_type,
120 MachException::Name(exc_type), exc_data_count,
121 (exc_data_count > 0 ? exc_datas[0] : 0xBADDBADD),
122 (exc_data_count > 1 ? exc_datas[1] : 0xBADDBADD));
123 }
124 g_message->exc_type = 0;
125 g_message->exc_data.clear();
126
127 if (task_port == g_message->task_port) {
128 g_message->task_port = task_port;
129 g_message->thread_port = thread_port;
130 g_message->exc_type = exc_type;
131 AppendExceptionData(g_message->exc_data, exc_data, exc_data_count);
132 return KERN_SUCCESS;
133 } else if (!MachTask::IsValid(g_message->task_port)) {
134 // Our original exception port isn't valid anymore check for a SIGTRAP
135 if (exc_type == EXC_SOFTWARE && exc_data_count == 2 &&
136 exc_data[0] == EXC_SOFT_SIGNAL && exc_data[1] == SIGTRAP) {
137 // We got a SIGTRAP which indicates we might have exec'ed and possibly
138 // lost our old task port during the exec, so we just need to switch over
139 // to using this new task port
140 g_message->task_port = task_port;
141 g_message->thread_port = thread_port;
142 g_message->exc_type = exc_type;
143 AppendExceptionData(g_message->exc_data, exc_data, exc_data_count);
144 return KERN_SUCCESS;
145 }
146 }
147 return KERN_FAILURE;
148}
149
150void MachException::Message::Dump() const {
151 DNBLogThreadedIf(LOG_EXCEPTIONS, " exc_msg { bits = 0x%8.8x size = 0x%8.8x "
152 "remote-port = 0x%8.8x local-port = 0x%8.8x "
153 "reserved = 0x%8.8x id = 0x%8.8x } ",
154 exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size,
155 exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port,
156 exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id);
157
158 DNBLogThreadedIf(LOG_EXCEPTIONS, "reply_msg { bits = 0x%8.8x size = 0x%8.8x "
159 "remote-port = 0x%8.8x local-port = 0x%8.8x "
160 "reserved = 0x%8.8x id = 0x%8.8x }",
161 reply_msg.hdr.msgh_bits, reply_msg.hdr.msgh_size,
162 reply_msg.hdr.msgh_remote_port,
163 reply_msg.hdr.msgh_local_port, reply_msg.hdr.msgh_reserved,
164 reply_msg.hdr.msgh_id);
165
166 state.Dump();
167}
168
169bool MachException::Data::GetStopInfo(
170 struct DNBThreadStopInfo *stop_info) const {
171 // Zero out the structure.
172 memset(stop_info, 0, sizeof(struct DNBThreadStopInfo));
173
174 if (exc_type == 0) {
175 stop_info->reason = eStopTypeInvalid;
176 return true;
177 }
178
179#if defined(__arm64__) || defined(__aarch64__)
180 if (exc_type == EXC_BREAKPOINT && exc_data[0] == EXC_ARM_DA_DEBUG &&
181 exc_data.size() > 1) {
182 stop_info->reason = eStopTypeWatchpoint;
183 stop_info->details.watchpoint.mach_exception_addr = exc_data[1];
184 stop_info->details.watchpoint.addr = INVALID_NUB_ADDRESS;
185 if (exc_data.size() > 2) {
186 stop_info->details.watchpoint.hw_idx = exc_data[2];
187 }
188 return true;
189 }
190#endif
191
192 // We always stop with a mach exceptions
193 stop_info->reason = eStopTypeException;
194 // Save the EXC_XXXX exception type
195 stop_info->details.exception.type = exc_type;
196
197 // Fill in a text description
198 const char *exc_name = MachException::Name(exc_type);
199 char *desc = stop_info->description;
200 const char *end_desc = desc + DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH;
201 if (exc_name)
202 desc +=
203 snprintf(desc, DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH, "%s", exc_name);
204 else
205 desc +=
206 snprintf(desc, DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH, "%i", exc_type);
207
208 stop_info->details.exception.data_count = exc_data.size();
209
210 int soft_signal = SoftSignal();
211 if (soft_signal) {
212 if (desc < end_desc) {
213 const char *sig_str = SysSignal::Name(soft_signal);
214 snprintf(s: desc, maxlen: end_desc - desc, format: " EXC_SOFT_SIGNAL( %i ( %s ))",
215 soft_signal, sig_str ? sig_str : "unknown signal");
216 }
217 } else {
218 // No special disassembly for exception data, just
219 size_t idx;
220 if (desc < end_desc) {
221 desc += snprintf(s: desc, maxlen: end_desc - desc, format: " data[%llu] = {",
222 (uint64_t)stop_info->details.exception.data_count);
223
224 for (idx = 0;
225 desc < end_desc && idx < stop_info->details.exception.data_count;
226 ++idx)
227 desc += snprintf(
228 desc, end_desc - desc, "0x%llx%c", (uint64_t)exc_data[idx],
229 ((idx + 1 == stop_info->details.exception.data_count) ? '}' : ','));
230 }
231 }
232
233 // Copy the exception data
234 size_t i;
235 for (i = 0; i < stop_info->details.exception.data_count; i++)
236 stop_info->details.exception.data[i] = exc_data[i];
237
238 return true;
239}
240
241void MachException::Data::DumpStopReason() const {
242 int soft_signal = SoftSignal();
243 if (soft_signal) {
244 const char *signal_str = SysSignal::Name(soft_signal);
245 if (signal_str)
246 DNBLog("signal(%s)", signal_str);
247 else
248 DNBLog("signal(%i)", soft_signal);
249 return;
250 }
251 DNBLog("%s", Name(exc_type));
252}
253
254kern_return_t MachException::Message::Receive(mach_port_t port,
255 mach_msg_option_t options,
256 mach_msg_timeout_t timeout,
257 mach_port_t notify_port) {
258 DNBError err;
259 const bool log_exceptions = DNBLogCheckLogBit(LOG_EXCEPTIONS);
260 mach_msg_timeout_t mach_msg_timeout =
261 (options & MACH_RCV_TIMEOUT) ? timeout : 0;
262 if (log_exceptions && ((options & MACH_RCV_TIMEOUT) == 0)) {
263 // Dump this log message if we have no timeout in case it never returns
264 DNBLogThreaded("::mach_msg ( msg->{bits = %#x, size = %u remote_port = "
265 "%#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, option "
266 "= %#x, send_size = 0, rcv_size = %llu, rcv_name = %#x, "
267 "timeout = %u, notify = %#x)",
268 exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size,
269 exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port,
270 exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id, options,
271 (uint64_t)sizeof(exc_msg.data), port, mach_msg_timeout,
272 notify_port);
273 }
274
275 err = ::mach_msg(&exc_msg.hdr,
276 options, // options
277 0, // Send size
278 sizeof(exc_msg.data), // Receive size
279 port, // exception port to watch for exception on
280 mach_msg_timeout, // timeout in msec (obeyed only if
281 // MACH_RCV_TIMEOUT is ORed into the
282 // options parameter)
283 notify_port);
284
285 // Dump any errors we get
286 if (log_exceptions) {
287 err.LogThreaded("::mach_msg ( msg->{bits = %#x, size = %u remote_port = "
288 "%#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, "
289 "option = %#x, send_size = %u, rcv_size = %u, rcv_name = "
290 "%#x, timeout = %u, notify = %#x)",
291 exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size,
292 exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port,
293 exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id, options, 0,
294 sizeof(exc_msg.data), port, mach_msg_timeout, notify_port);
295 }
296 return err.Status();
297}
298
299bool MachException::Message::CatchExceptionRaise(task_t task) {
300 bool success = false;
301 state.task_port = task;
302 g_message = &state;
303 // The exc_server function is the MIG generated server handling function
304 // to handle messages from the kernel relating to the occurrence of an
305 // exception in a thread. Such messages are delivered to the exception port
306 // set via thread_set_exception_ports or task_set_exception_ports. When an
307 // exception occurs in a thread, the thread sends an exception message to
308 // its exception port, blocking in the kernel waiting for the receipt of a
309 // reply. The exc_server function performs all necessary argument handling
310 // for this kernel message and calls catch_exception_raise,
311 // catch_exception_raise_state or catch_exception_raise_state_identity,
312 // which should handle the exception. If the called routine returns
313 // KERN_SUCCESS, a reply message will be sent, allowing the thread to
314 // continue from the point of the exception; otherwise, no reply message
315 // is sent and the called routine must have dealt with the exception
316 // thread directly.
317 if (mach_exc_server(&exc_msg.hdr, &reply_msg.hdr)) {
318 success = true;
319 } else if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) {
320 DNBLogThreaded("mach_exc_server returned zero...");
321 }
322 g_message = NULL;
323 return success;
324}
325
326kern_return_t MachException::Message::Reply(MachProcess *process, int signal) {
327 // Reply to the exception...
328 DNBError err;
329
330 // If we had a soft signal, we need to update the thread first so it can
331 // continue without signaling
332 int soft_signal = state.SoftSignal();
333 if (soft_signal) {
334 int state_pid = -1;
335 if (process->Task().TaskPort() == state.task_port) {
336 // This is our task, so we can update the signal to send to it
337 state_pid = process->ProcessID();
338 soft_signal = signal;
339 } else {
340 err = ::pid_for_task(state.task_port, &state_pid);
341 }
342
343 assert(state_pid != -1);
344 if (state_pid != -1) {
345 errno = 0;
346 if (::ptrace(PT_THUPDATE, state_pid,
347 (caddr_t)((uintptr_t)state.thread_port), soft_signal) != 0)
348 err.SetError(errno, DNBError::POSIX);
349 else
350 err.Clear();
351
352 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail())
353 err.LogThreaded("::ptrace (request = PT_THUPDATE, pid = 0x%4.4x, tid = "
354 "0x%4.4x, signal = %i)",
355 state_pid, state.thread_port, soft_signal);
356 }
357 }
358
359 DNBLogThreadedIf(
360 LOG_EXCEPTIONS, "::mach_msg ( msg->{bits = %#x, size = %u, remote_port = "
361 "%#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, "
362 "option = %#x, send_size = %u, rcv_size = %u, rcv_name = "
363 "%#x, timeout = %u, notify = %#x)",
364 reply_msg.hdr.msgh_bits, reply_msg.hdr.msgh_size,
365 reply_msg.hdr.msgh_remote_port, reply_msg.hdr.msgh_local_port,
366 reply_msg.hdr.msgh_reserved, reply_msg.hdr.msgh_id,
367 MACH_SEND_MSG | MACH_SEND_INTERRUPT, reply_msg.hdr.msgh_size, 0,
368 MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
369
370 err = ::mach_msg(&reply_msg.hdr, MACH_SEND_MSG | MACH_SEND_INTERRUPT,
371 reply_msg.hdr.msgh_size, 0, MACH_PORT_NULL,
372 MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
373
374 if (err.Fail()) {
375 if (err.Status() == MACH_SEND_INTERRUPTED) {
376 if (DNBLogCheckLogBit(LOG_EXCEPTIONS))
377 err.LogThreaded("::mach_msg() - send interrupted");
378 // TODO: keep retrying to reply???
379 } else {
380 if (state.task_port == process->Task().TaskPort()) {
381 DNBLogThreaded("error: mach_msg() returned an error when replying to a "
382 "mach exception: error = %u",
383 err.Status());
384 } else {
385 if (DNBLogCheckLogBit(LOG_EXCEPTIONS))
386 err.LogThreaded("::mach_msg() - failed (child of task)");
387 }
388 }
389 }
390
391 return err.Status();
392}
393
394void MachException::Data::Dump() const {
395 const char *exc_type_name = MachException::Name(exc_type);
396 DNBLogThreadedIf(
397 LOG_EXCEPTIONS, " state { task_port = 0x%4.4x, thread_port = "
398 "0x%4.4x, exc_type = %i (%s) ...",
399 task_port, thread_port, exc_type, exc_type_name ? exc_type_name : "???");
400
401 const size_t exc_data_count = exc_data.size();
402 // Dump any special exception data contents
403 int soft_signal = SoftSignal();
404 if (soft_signal != 0) {
405 const char *sig_str = SysSignal::Name(soft_signal);
406 DNBLogThreadedIf(LOG_EXCEPTIONS,
407 " exc_data: EXC_SOFT_SIGNAL (%i (%s))",
408 soft_signal, sig_str ? sig_str : "unknown signal");
409 } else {
410 // No special disassembly for this data, just dump the data
411 size_t idx;
412 for (idx = 0; idx < exc_data_count; ++idx) {
413 DNBLogThreadedIf(LOG_EXCEPTIONS, " exc_data[%llu]: 0x%llx",
414 (uint64_t)idx, (uint64_t)exc_data[idx]);
415 }
416 }
417}
418
419// The EXC_MASK_ALL value hard-coded here so that lldb can be built
420// on a new OS with an older deployment target . The new OS may have
421// an addition to its EXC_MASK_ALL that the old OS will not recognize -
422// <mach/exception_types.h> doesn't vary the value based on the deployment
423// target. So we need a known set of masks that can be assumed to be
424// valid when running on an older OS. We'll fall back to trying
425// PREV_EXC_MASK_ALL if the EXC_MASK_ALL value lldb was compiled with is
426// not recognized.
427
428#define PREV_EXC_MASK_ALL (EXC_MASK_BAD_ACCESS | \
429 EXC_MASK_BAD_INSTRUCTION | \
430 EXC_MASK_ARITHMETIC | \
431 EXC_MASK_EMULATION | \
432 EXC_MASK_SOFTWARE | \
433 EXC_MASK_BREAKPOINT | \
434 EXC_MASK_SYSCALL | \
435 EXC_MASK_MACH_SYSCALL | \
436 EXC_MASK_RPC_ALERT | \
437 EXC_MASK_RESOURCE | \
438 EXC_MASK_GUARD | \
439 EXC_MASK_MACHINE)
440
441#define LLDB_EXC_MASK EXC_MASK_ALL
442
443kern_return_t MachException::PortInfo::Save(task_t task) {
444 DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE,
445 "MachException::PortInfo::Save ( task = 0x%4.4x )", task);
446 // Be careful to be able to have debugserver built on a newer OS than what
447 // it is currently running on by being able to start with all exceptions
448 // and back off to just what is supported on the current system
449 DNBError err;
450
451 mask = LLDB_EXC_MASK;
452
453 count = (sizeof(ports) / sizeof(ports[0]));
454 err = ::task_get_exception_ports(task, mask, masks, &count, ports, behaviors,
455 flavors);
456 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail())
457 err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = 0x%x, "
458 "maskCnt => %u, ports, behaviors, flavors )",
459 task, mask, count);
460
461 if (err.Status() == KERN_INVALID_ARGUMENT && mask != PREV_EXC_MASK_ALL) {
462 mask = PREV_EXC_MASK_ALL;
463 count = (sizeof(ports) / sizeof(ports[0]));
464 err = ::task_get_exception_ports(task, mask, masks, &count, ports,
465 behaviors, flavors);
466 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail())
467 err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = "
468 "0x%x, maskCnt => %u, ports, behaviors, flavors )",
469 task, mask, count);
470 }
471 if (err.Fail()) {
472 mask = 0;
473 count = 0;
474 }
475 return err.Status();
476}
477
478kern_return_t MachException::PortInfo::Restore(task_t task) {
479 DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE,
480 "MachException::PortInfo::Restore( task = 0x%4.4x )", task);
481 uint32_t i = 0;
482 DNBError err;
483 if (count > 0) {
484 for (i = 0; i < count; i++) {
485 err = ::task_set_exception_ports(task, masks[i], ports[i], behaviors[i],
486 flavors[i]);
487 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) {
488 err.LogThreaded("::task_set_exception_ports ( task = 0x%4.4x, "
489 "exception_mask = 0x%8.8x, new_port = 0x%4.4x, "
490 "behavior = 0x%8.8x, new_flavor = 0x%8.8x )",
491 task, masks[i], ports[i], behaviors[i], flavors[i]);
492 // Bail if we encounter any errors
493 }
494
495 if (err.Fail())
496 break;
497 }
498 }
499 count = 0;
500 return err.Status();
501}
502
503const char *MachException::Name(exception_type_t exc_type) {
504 switch (exc_type) {
505 case EXC_BAD_ACCESS:
506 return "EXC_BAD_ACCESS";
507 case EXC_BAD_INSTRUCTION:
508 return "EXC_BAD_INSTRUCTION";
509 case EXC_ARITHMETIC:
510 return "EXC_ARITHMETIC";
511 case EXC_EMULATION:
512 return "EXC_EMULATION";
513 case EXC_SOFTWARE:
514 return "EXC_SOFTWARE";
515 case EXC_BREAKPOINT:
516 return "EXC_BREAKPOINT";
517 case EXC_SYSCALL:
518 return "EXC_SYSCALL";
519 case EXC_MACH_SYSCALL:
520 return "EXC_MACH_SYSCALL";
521 case EXC_RPC_ALERT:
522 return "EXC_RPC_ALERT";
523#ifdef EXC_CRASH
524 case EXC_CRASH:
525 return "EXC_CRASH";
526#endif
527 case EXC_RESOURCE:
528 return "EXC_RESOURCE";
529#ifdef EXC_GUARD
530 case EXC_GUARD:
531 return "EXC_GUARD";
532#endif
533#ifdef EXC_CORPSE_NOTIFY
534 case EXC_CORPSE_NOTIFY:
535 return "EXC_CORPSE_NOTIFY";
536#endif
537#ifdef EXC_CORPSE_VARIANT_BIT
538 case EXC_CORPSE_VARIANT_BIT:
539 return "EXC_CORPSE_VARIANT_BIT";
540#endif
541 default:
542 break;
543 }
544 return NULL;
545}
546
547// Returns the exception mask for a given exception name.
548// 0 is not a legit mask, so we return that in the case of an error.
549exception_mask_t MachException::ExceptionMask(const char *name) {
550 static const char *exception_prefix = "EXC_";
551 static const int prefix_len = strlen(exception_prefix);
552
553 // All mach exceptions start with this prefix:
554 if (strstr(name, exception_prefix) != name)
555 return 0;
556
557 name += prefix_len;
558 std::string name_str = name;
559 if (name_str == "BAD_ACCESS")
560 return EXC_MASK_BAD_ACCESS;
561 if (name_str == "BAD_INSTRUCTION")
562 return EXC_MASK_BAD_INSTRUCTION;
563 if (name_str == "ARITHMETIC")
564 return EXC_MASK_ARITHMETIC;
565 if (name_str == "EMULATION")
566 return EXC_MASK_EMULATION;
567 if (name_str == "SOFTWARE")
568 return EXC_MASK_SOFTWARE;
569 if (name_str == "BREAKPOINT")
570 return EXC_MASK_BREAKPOINT;
571 if (name_str == "SYSCALL")
572 return EXC_MASK_SYSCALL;
573 if (name_str == "MACH_SYSCALL")
574 return EXC_MASK_MACH_SYSCALL;
575 if (name_str == "RPC_ALERT")
576 return EXC_MASK_RPC_ALERT;
577#ifdef EXC_CRASH
578 if (name_str == "CRASH")
579 return EXC_MASK_CRASH;
580#endif
581 if (name_str == "RESOURCE")
582 return EXC_MASK_RESOURCE;
583#ifdef EXC_GUARD
584 if (name_str == "GUARD")
585 return EXC_MASK_GUARD;
586#endif
587#ifdef EXC_CORPSE_NOTIFY
588 if (name_str == "CORPSE_NOTIFY")
589 return EXC_MASK_CORPSE_NOTIFY;
590#endif
591 return 0;
592}
593

source code of lldb/tools/debugserver/source/MacOSX/MachException.cpp